Durin is the eldest of the Seven Fathers of the Dwarves in J.R.R. Tolkien’s legendarium.
In Tolkien’s creation story, the Vala Aulë makes the Seven Fathers of the Dwarves before the awakening of the Elves. Ilúvatar grants them independent life, and they are eventually placed beneath the earth to await their appointed time. Durin is the first and eldest of these fathers.
Durin awakens at Mount Gundabad in the north of Middle-earth and later establishes Khazad-dûm, the great underground city beneath the Misty Mountains. Because his descendants preserve his name and likeness through successive rulers, several dwarf kings are called Durin. The line is therefore known as the Longbeards, or the Durin’s Folk.
Thorin Oakenshield and Dáin Ironfoot are later members of this wider lineage, not the original father of the dwarf race. Telchar is a famous smith of Nogrod, another dwarf city, and is also not one of the Seven Fathers.